f  7.  :>".-;£  J 


March  26,  1M11. 


U.  S.  DEPARTMENT  OF   AGRICULTURE, 

BUREAU  OF  ENTOMOLOGY— CIRCULAR  No.  135. 

L.  O.  HOWARD,  Entomologist  and  Chief  of  Bureau. 


THE  ASPARAGUS  MINER. 


F.  II.  CHITTENDEN,  Sc.  I>.. 

In  (  harge  of  Truck  Crop  and  Ston  d  Product  I  ■  stigations. 


79779°— U 


WASHINGTON   :  GOVERNMENT  PRINTING  OFFICE  I  IB1I 


U.S.  DEPi 


B  UREA  U  OF  EX  TOM"  LOG  Y. 

L.  0.  Howard,  Entomologist  and  Chief  of  Bureau. 

C.  L.  Mablatt.  Entomologist  and  Acting  Chief  in  Absence  of  Chief . 

R.  S.  Clifton,  Executive  Assistant. 

W.  F.  Tastet,   Chief  Clerk. 

F.  H.  Chittenden,  in  charge  of  truck  crop  and  stored  product  insect  investigations. 

A.  D.  Hopkins,  in  charge  of  forest  insect  investigations. 

W.  D.  Hunteb.  in  charge  of  southern  field  crop  insect  investigations. 

F.  M.  Webster,  in  charge  of  cereal  and  forage  insect  investigations. 

A.  L.  Quaintance.  in  charge  of  deciduous  fruit  insect  investigations. 

E.  F.  Phillips,  in  charge  of  bee  cub 

D.  M.  Rogers,  in  charge  of  preventing  spread  of  moths,  field  work. 

Rolla  P.  Ccbbie,  in  charge  of  editorial  wort. 

Mabel  Colcoed,  librarian. 

Tecck  Ceop  and  Stobed  Pboduct  Insect  Investigations. 
F.  H.  'hittenden.  in  charge. 

H.  M.  Russell.  G.  H.  Popenoe.  D.  K.  McMillan.  E.  G.  Smyth.  Thos.  H.  Jones. 

M.  M.   High.   Feed.   A.  Johnston.  Wm.   B.   Parker.   H.   0.   Marsh,  agents  and 

experts. 
I.  J.  Condit.  collaborator  in  Califon 
P.  T.  Cole,  collaborator  in  tidewater  Virginia. 


CIRCULAR  NO.  135.  Issued  March  25,  1611. 

United  States  Department  of  Agriculture, 

BUREAU    OF   ENTOMOLOGY. 
L.  O.  HOWARD,  Entomologist  and  Chief  of  Bureau. 


THE   ASPARAGUS    MINER.' 

{Agromyza  simplex  Loew.) 

By  1'   II    <  mi  ii  \m  \.  Sc.  1'  , 
In  Charge  of  Truck  Crop  and  Stored  Product  Insect  Investigations. 

The  stalks  of  asparagus  are  frequently  attacked  by  insects,  ami  in 
recent  years  have  boon  report  ed  considerably  injured  by  the  larva  or 
maggot  of  a  minute  Mack  fly  to  which  the  name  asparagus  miner  has 
beengiven.  The  larva  mines  beneath  the  epidermis  of  the  stalk,  ami 
when  it  has  t  ransl'ormed  to  the  puparium  or  "flaxseed'1  stage  the  thin 
outer  skin  hecomes  more  or  less  ruptured  and  the  presence  of  the 
insect  is  easily  detected.     It  operates  more  abundantly  near  the  base 


Fig.  1.— The  asparagus  miner  (Agromyza simplex):  Fly.  dorsal  view  at  left,  lateral  view  at  ripht.     Highly 
magnified.    (Author's  Illustration 

of  the  stalks  and  penetrates  below  the  surface  of  the  ground  t<>  a 
depth  of  7  m-  s  inches.  During  the  year  I '.Kid  this  species  attracted 
considerable  attention  by  its  abundance  in  some  of  the  principal 
asparagus-grovi  ing  seel  ions  of  New  England  and  it  bids  fair  to  become 
a  pest  of  considerable  importance.  It  was  first  noticed  on  asparagus 
in  1896,  prior  to  which  time  nothing  was  known  of  its  habits.  It  isa 
native  species  and  evidently  restricted  to  asparagus  as  a  food  plant. 
Until  the  year  L906  it  had  not  been  recognized  as  doing  injury  to 
cutting  beds,  although  attack  had  been  observed  in  various  sections. 

a  Revised  reprint  from  Bui.  6G,  n.  ^.,  Bur.  Em.,  U.  S.  Dept.  A 

79779°— CU".  135-11  1 


THE  ASPARAGUS   MINER. 


The  mines  of  the  larvae  about  and  below  the  bases  of  the  stalks  are 
frequently  so  abundant  that  they  have  the  effect  of  girdling,  so  that 
the  injured  stalks  can  readily  be  pulled  from  the  ground. 

DESCRIPTIVE. 

The  parent  insect  is  a  two- winged  fly  (fig.  1),  metallic  black,  with 
large  prominent  head  and  eyes,  and  clear  wings,  the  wing  expanse 
being  about  one-sixth  of  an  inch  (4  mm.). 

The  larva  (fig.  2,  a)  is  about  one-fifth  of  an  inch  long  and  milk- 
white   in   color.     Like   other  maggots,   it   is  footless,   large   at   the 

posterior    extremity,   and    tapering 
toward  the  head. 

The  puparium  (fig.  2,  d,  e)  is  not 
unlike  the  "flaxseed"  of  the  perni- 
cious Hessian  fly,  with  which  it  has 
been  aptly  compared.  At  a  little 
distance,  also,  it  suggests  a  Lecanium 
scale.  This  stage  is  remarkable  be- 
cause of  its  peculiar  flattened  and 
curved  position,  as  seen  from  the 
side.  It  is  red  in  color,  and  meas- 
ures about  3.5  mm.  in  length  and 
about  1  mm.  in  width. 

The  egg  has  not  been  observed. 
This  species  belongs  to  the  dipter- 
ous family  Agromyzidae,  and  was  described  by  Loew  in  1861,°  the 
locality  being  given  as  "Middle  States." 

DISTRIBUTION. 

In  its  injurious  occurrences  this  species  appears  to  be  limited  to  the 
eastern  United  States,  from  New  England  to  Tennessee.  From  avail- 
able data  it  is  quite  obvious,  however,  that  it  may  be  destructive  over 
a  considerable  territory,  including  a  large  portion  of  Massachusetts 
and  Connecticut,  Long  Island,  the  District  of  Columbia,  Pennsyl- 
vania, and  Tennessee.  As  it  is  recorded  from  New  Jersey,  it  is  prob- 
ably injurious  there,  although  no  reports  of  injury  in  that  State  have 
reached  this  office.  In  time  it  will  doubtless  attract  attention  in 
intermediate  points  and  in  States  farther  north  and  west.  It  has  also 
appeared  in  asparagus  beds  in  California. 

HISTORICAL   AND    BIOLOGICAL    NOTES. 

In  May,  1897,  and  afterwards  this  fly  was  observed  in  abundance 
by  the  writer  on  terminal  shoots  of  asparagus,  particularly  at  Cabin 
John,  Md.     Two  weeks  later  no  more  flies  were  seen,  but  June  26 


Fig.  2.— The  asparagus  miner  (Agromyza  sim- 
plex): a,  Larva,  lateral  view;  b,  thoracic  spir- 
acles; c,  anal  spiracles;  d,  puparium  from  side; 
e,  same  from  above;  /,  section  of  asparagus 
stalk,  showing  injury  and  location  of  puparia 
on  detached  section,  a-e,  Much  enlarged:  /, 
slightly  reduced.    (Author's  illustration.) 


a  Diptera  Americse  eeptentrionalie  indigena,  Centuria  octava  84,  p.  160. 


THK   ASPARAGUS   MI  NEK.  6 

they  reappeared  and  were  then  usually  seen  in  copula.  It  was  sur- 
mised ai  the  time  that  this  second  appearance  indicated  the  Brsl  new 
generation  of  the  year  and  its  abundance  on  asparagus  seemed  to  show 
that  it  lived  in  some  manner  at  t  he  expense  of  thai  plant .  Examina- 
tion of  asparagus  plants  at  that  time,  howev  er,  Failed  to  show  at  tack.0 
In  1900  complaints  of  injuries  were  made  in  the  1  >istrict  of  Colum- 
bia, aud  at    Know  die,  Tenn..  and  in  the  meantime  the  species  came 

under  the  observation  of  Mr.  1''.  A.  Sirrine,  who  stated''  that  work 
was  lirst  observed  in  asparagus  fields  on  Long  Island  in  L896.  Late 
in  September,  1900,  word  was  received  of  injury  to  asparagus  from 
Tennallytown,  I).  C.  When  the  writer  visited  the  held,  although 
injury  was  apparent  on  the  outer  skin  of  some  st;dk>.  no  living 
specimens  could  he  ohtained,  only  the  dried  pup  aria  being  in  e\  idence 
at  that  time.  October  2  of  the  same  year,  Mr.  Samuel  M.  Baiu, 
Qniversitj  of  Tennessee,  Know  die,  Tenn.,  sent  a  stalk  of  asparagus 
showing  the  work  of  this  miner  upon  the  skin,  and,  October  27, 
specimens  of  the  dried  puparia. 

February  IS,  1001,  it  was  reported  at  Philadelphia,  Pa.,  that  this 
insect  seemed  to  cause  much  greater  trouble  than  the  common 
asparagus  beetle.  Two  or  three  new  beds  of  asparagus  were  lost  on 
account  of  its  ravages. 

By  the  writer's  direction,  Mr.  F.  C.  Pratt  visited  a  truck  farm  at 
Brookland,  I).  ('.,  where  asparagus  was  one  of  the  main  crops,  June 
18,  1902.  Asparagus  was  still  being  cut  for  market,  but  volunteer 
plants  were  growing  here  and  there  in  fields  of  corn,  cantaloupe,  and 
potatoes,  between  rows.  A  few  flies  were  seen  on  terminal  shoots  of 
asparagus  that  showed  wilting,  ami  many  volunteer  plant-  were 
badly  infested,  most  individuals  having  transformed  to  pupse. 
Although  stems  break  oil'  jusl  below  the  ground,  the  entire  colony  of 
insects  below  that  point  is  left  with  sullicient  moisture  and  nourish- 
ment for  their  maintenance.  The  puparia  were  presenl  in  great 
numbers  underneath  the  outer  skin  of  the  root,  and  as  many  as  nine 
puparia  were  counted  in  a  space  only  an  inch  long  on  one  stalk.  The 
stalks  below  the  point  of  injurv  appeared  to  be  perfectly  sound. 
Larva'  also  were  found  in  rotting  stalks  that  broke  off  just  below 
ground. 

During  September,  1906,  Messrs.  J.  B.  Norton  and  A.  1).  Shamel, 
of  the  Bureau  of  Plant  Industry,  furnished  stems  of  asparagus  from 
Concord,  Mass..  showing  severe  infestation  by  this  species,  many 
puparia  being  presenl  under  the  mined  outer  skin.  In  the  neighbor- 
hood of  Concord,  a  very  important  asparagus-growing  region  where 
hundreds  of  acres  are  devoted  to  this  crop,  infestation  was  practi- 
cally absolute,  the  insect  being  as  abundant  as  the  common  asparagus 

"Bui.  10,  n.  *.,  Div.  Km  .  I"    S.  Dept.  Agric,  p.  62,  1898. 
&Bul.  180,  X.  V.  Agric.  Exp.  Sta.,  p.  J77,  Geneva,  1900. 


4  THE   ASPARAGUS    MINER. 

beetle,  and  present  wherever  rust  was  found,  as  also  where  no  rust 
was  present.     Some  plants  showed  injury  7  inches  below  the  surface. 

Later  Mr.  Shamel  reported  finding  infestation  in  every  field  and 
patch  of  asparagus  which  he  visited  in  Massachusetts  and  Connect- 
icut, particularly  at  Suffield,  Granby,  and  Hartford.  Conn.,  and  he 
believed  attack  to  be  widespread." 

October  26,  1006,  Mr.  Ralph  E.  Smith  wrote  that  the  conditions 
under  which  this  asparagus  miner  was  found  in  abundance  in  the 
yellow  stalks  of  asparagus  in  California,  as  reported  by  him  in  an 
article  on  Asparagus  Rust  Control, b  had  prevailed  for  two  or  three 
years.  The  insect  was  always  very  abundant  at  the  base  of  yellow, 
dying  stalks,  although  injury  was  attributed  to  the  "centipede," 
reported  as  wireworms  on  a  previous  occasion.0 

The  asparagus  miner  was  reported  by  Mr.  I.  J.  Condit  in  the  vicinity 
of  Antioch,  Cal.,  August  10,  1008,  where  the  common  asparagus  beetle 
was  also  abundant.  The  miner  was  equally  numerous  and  stalks 
showing  infestation  were  received.  The  miner-infested  stalks  could 
generally  be  detected  by  their  roughened  appearance  near  the  ground- 
This  species  was  also  taken  at  Oakley,  and  it  seems  probable  that  it 
is  becoming  generally  distributed  in  California.  In  one  place  at 
Oakley  Mr.  Condit  observed  the  miner  cpiite  common  on  some  stalks. 

During  October,  1008,  the  writer  observed  this  species  well  estab- 
lished on  asparagus  in  the  vicinity  of  Portsmouth,  Va.  In  October, 
also,  very  severe  injury  was  reported  to  asparagus  in  the  vicinity  of 
Concord,  Mass.  The  roots  of  the  plants  were  not  only  girdled,  but 
the  miners  worked  up  the  stalks  some  inches  above  the  ground. 

REMEDIAL    MEASURES. 

With  our  present  knowledge  of  the  life  economy  of  this  species, 
two  methods  of  control  suggest  themselves  as  of  greatest  value,  and  it 
may  be  that  they  will  prove  all  that  is  necessary  under  ordinary 
conditions. 

(1)  In  spring  permit  a  few  volunteer  asparagus  plants  to  grow  as 
a  trap  crop,  to  lure  the  fly  from  the  main  crop  or  the  cutting  beds 
for  the  deposition  of  her  eggs.  After  this  has  been  accomplished 
the  trap  crop  should  be  destroyed  by  pulling  the  infested  plants  and 
burning  them  with  their  contained  puparia.  The  time  to  pull  the 
plants  will  vary  according  to  locality  and  somewhat  according  to 
season  also.  The  second  and  third  week  in  June  would  be  about  the 
right  time  in  and  near  the  District  of  Columbia.  On  Long  Island 
this  work  should  be  done  a  week  or  two  later.     In  the  northernmost 

°Its  occurrence  at  New  Haven,  Conn.,  is  recorded  by  W.  E.  Britton  (Gth  Kept. 
State  Ent.  Conn,  for  1906,  pp.  303-306,  1907). 
^  Bui.  172,  Univ.  Cal.  Agric.  Exp.  Sta.,  p.  21. 
<Bul.  165,  loc.  cit. 


MARSTON  SCIENCE  LIBRARY 


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